Q.
A hydrocarbon CxHy undergoes complete combustion with required amount of oxygen to produce CO2 and H2O. If the ratio of masses of hydrocarbon burnt to oxygen gas consumed comes out to be 29:104, then value of (x+y) is :
Hydrocarbon CxHy undergoes complete combustion according to the balanced chemical equation : CxHy+(x+4y)O2⟶CO2+2yH2O
From the above equation, it is clear that : Mass of O2 consumed Mass of CxHy burnt =(x+4y)3212x+y
But, this ratio is given as 29:104. ∴(x+4y)3212x+y=10429
On solving, we get x:y=2:5.
But, there exists no hydrocarbon with formula C2H5. ∴ Molecular formula of hydrocarbon is C4H10 ∴x=4,y=10